An anti-government protester is taken away on a motorcycle by other demonstrators after injuring his leg during clashes with security forces in Caracas Venezuela Thursday

While Venezuelan leaders have lashed out at US presidents frequently in the past, Maduro had largely been careful not to antagonize Trump.

But Mr Trump's repeated criticisms of the troubled South American nation appear to have struck a nerve. He served time for murder 30 years ago and was implicated in at least two other murders yet continued to rise in Venezuela's murky security services.

During Maduro's visit to the White House on Thursday, Trump expressed dismay at how once-booming Venezuela was now mired in poverty, saying "it's been unbelievably poorly run" and calling the humanitarian situation "a disgrace to humanity".

Anti-government demonstrators have been on the streets daily since early April to press for elections, blaming Maduro for an economic crisis that has caused severe shortages of food and medicine. Maduro has said he had no prior knowledge of the Supreme Court ruling against congress in March, pointing to the objections raised by Venezuela's chief prosecutor as proof the country's institutions operate independently. The decision was later partially reversed, though it did not stop the unrest.

A spokeswoman for Russia's Foreign Ministry said Friday the nation continues to believe dialogue is the best way to resolve the upheaval, while also urging both the government and opposition to act "in line with the law".

"It's not necessary, pertinent, or convenient to carry out a transformation of the state in the terms that a new constitution could imply", she wrote.

The Labour leader has said nothing about the unfolding crisis in Venezuela, which has seen troops deployed by embattled leader Nicolas Maduro to quell the growing unrest. Maikel Moreno, the president of Venezuela's Supreme Court, and among those sanctioned by the US government, said Friday that Trump's executive order was an attempt to impose its authority over Venezuela's institutions and compromise the judicial branch's independence. She said the order was one more example of USA attempts to destabilize Venezuela's government, adding that Maduro strongly backs the Supreme Court magistrates who are "victims of US imperial power". In February, the target was Vice President Tareck El Aissami, whom US officials accuse of being involved in worldwide drug trafficking. "Get your dirty hands out of here".

The Treasury cited recent Supreme Court rulings that have allowed Maduro to rule by executive decree, exempted the government from submitting its budget to the legislature, and taken away from the legislature the power to appoint the National Electoral Council.

(AP Photo/Ariana Cubillos). An anti-government protester raises his violin before National Guards, as he yells not to shoot at protesters, creating a brief pause during clashes in Caracas, Venezuela, Thursday, May 18, 2017. The blue shield at center is fashioned in the likeness of the cover of Venezuela's constitution.

The government and the opposition have accused each other of sending armed groups to sow violence in the protests.